The acetylcholine receptors purified from Electrophorus and Torpedo electric tissue are to be chemically characterized. The subunits are to be separated and their amino acid compositions, N-terminal amino acid sequences, carbohydrate and lipid contents determined and compared. The functionality of the isolated receptors will be tested by the effects of cholinergic ligands on the interactions of receptor with the permeating cations, Na ion and K ion. Conformational changes in receptor will be sought which correlate with permeability control.